An Analysis of flow characteristics of unconventional weaving traffic: Western Cape case Study

Date
2021-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: The objective of this study is to analyse the characteristics of unconventional weaving behaviour of traffic within freeway sections and propose remedial measures. Thereby gaining a more detailed understanding of unconventional weaving behaviour, causes and possible solutions. Unconventional weaving traffic is defined as weaving that is not conventional according to the definition in the USA Highway Capacity Manual. It refers to excessive lane changing or weaving that occurs as a result of the geometry of the road, illegal behaviour, disregard of traffic marking etc. For purposes of this study the South African National Road N1 in the Western Cape between the R300 on-rampand the Okavango Boulevard was selected as the case study. The section of the road under consideration experiences a high number ofunconventional weaving manoeuvres resulting from the short distance between successive on-ramps (R300, Okavango), an observed general disregard of the lane markingsby numerous motorists(at the R300 on-rampdiverge point) and geometry of the section of road (particularly because no auxiliary lanesare provided). A regression analysis together with fundamental traffic flow diagrams are developed and applied to the base case and proposed remedial actions. The results indicate that weaving within the case study area can be improved by increasing the capacity of the R300 onramp and maintaining a lane balance. It is also observed that weaving within this section is not only related to the operations of the road but is also linked to human behaviour that may not be modelled.
AFRIKAANSE OPSOMMING: Die doelstelling van hierdie studie is om onkonvensionele weefgedrag in verkeer te analiseer vir ’n spesifieke problematiese gevallestudie en om regstellende maatreëls voor te stel. Sodoende kan ’n beter begrip verkry word in verband met onkonvensionele weef gedrag. Onkonvensionele weef gedrag word gedefinieer as weef gedragwat nie as konvensioneel beskou word binne die VSA ‘Highway CapacityManual’nie. Dit verwys na oormatige baan verwisseling wat plaasvind as gevolg van pad uitleg, onwettige rygedrag, verontagsaming van verkeersmerke en verkeerstekens, ens. Die Suid-Afrikaanse nasionale weg,N1 in die Weskaap tussen die R300 oprit en die Okavango Boulevard is verkies vir hierdie gevallestudie. Op hierdie deel van die snelweg vind ’n hoe mate van onkonvesionele weef gedrag plaas as gevolg van die kortafstand tussen opeenvolgende opritte (R300, Okavango), ’n opvallende algemene verontagsaming van die baan merke deur baie motoriste (by die R300 oprit divergeer punt) en die geometrie van die stuk pad( veral omdat daar geen addisionele afvoer bane bestaannie). ’n Regressie analise tesame met fundamentele verkeersvloei diagramme word ontwikkel en word toegepas opdie huidige basis situasie asook tot die nuwe voorgestelde verbeterde situasie. Die resultate toon aan dat weef gedrag in die gevallestudie area verbeter kan word deur middel van ’n vergroting van kapasiteit van die R300 oprit en deur middel van ’n behoud van baan balans. Wat ook waargeneem word is dat weef gedrag binne die gevallestudie area nie net aandie padwerking gekoppelkan word nie, maar ook aan menslike rygedrag wat nie gemodelleer is nie.
Description
Thesis (MEng)--Stellenbosch University, 2021.
Keywords
Transportation Engineering, UCTD, Weaving areas (Traffic engineering), Traffic flow patterns
Citation